A Karyological Study of F1 Hybrids between Female Asp and Male Kutum (Leusiscus Aspius × Rutilus Kutum)

In this study, cytogenetic characteristics of F1 progeny produced by crossbreeding of female Asp and male Kutum (Leusiscus aspius × Rutilus frisii) were determined using the tissue-squashing method of kidney and giemsa staining. Nucleolus organizer regions were also localized using AgNO3. Chromosome number was determined from a total of 85 metaphases plates achieved from 20 hybrid specimens with an average weight of 49.7 ± 2.5 g (S.E). Karyogram and ideogram were arranged from the best metaphase plates. Different characteristics of karyotype including the number of chromosome arms, the length of short and long arms, the centromic index, the arm ratio, and the relative and total length of chromosomes were calculated. The number of diploid chromosomes and chromosome arms was 2n=50 and NF=80, respectively. The karyotypes consisted of 10 pairs of metacentric, 5 pairs of submetacentric, and 10 pairs of acrocentric to sub-telocentric (10 m+5 sm+10 a-t). The ranges of centromic index, arm ratio, and relative length were 0-0.443, 1.266-∞ and 2.265-6.554 μm, respectively. The total length of chromosomes in the haploid series was 29.98 μm. The longest and shortest chromosomes were a pair of submetacentric and telocentric chromosomes, respectively. Nucleolus organizer regions were localized on the ends of long arms of the longest pair of acro-centric. These findings confirmed that F1 hybrids inherited the number and type of chromosomes from their parents.